One-wire electrical selecting apparatus



March 7, 1933. L BRowNsTElN' ONE-WIRE ELECTRICAL SELECTINGA APPARATUS Fle'd March 11, 1929 Patented Mar. 7, 1933 vVQUNITED STATES lPATENT CFFICE LoUisBRowNsrEImor BROOKLYN, NEW'YORK, AssIGNoR To MONOPULSE TELETYPE CORPORATION, or NEW YORK, N. Y., A CORPORATION or NEW YORK r01`TE-W1ill3l`1 ELECTRICAL SELECTING APPARATUS Application filed March 11, 1929. Serial No. 346,036.

This invention relatesl to electrical selective systems such as are used in printing telegraph receiving apparatus, for automatically selecting and operating anyone of a number of difl'erent instrumentalities, and is particularly applicable to so-called marginal systems in which a single impulse at a time, of predetermined value is sent over a one-wire li'neforV selecting purposes. l Such marginal systems as have heretofore been known, as for instance, in connection with printing telegraph systems, have a limited range of selectivity, being usually incapable of selecting any one of more than three devices. They further lack thecertainty of operation which is so essential in devices of thecharacter here involved and are more or lessinehicient by reason ofthe danger'ofselecting more than one device in response to a single impulse. My invention contemplates, among other things, the provision of any number of selecting magnets, 'each vrespective. magnet being designed to have theintensity of its field neutralized, or reduced substantially to Zero, byav different marginal impulse sent over the line from the'distant source. The neutralization of the field of one magnet, magnetically releasesa selected varmature in respouseV to the impulse. My invention contemplates further, the provision of an auxiliary-magnet for positively operating the selected armature, on the release of the magnetic pull on that armature, to close a circuit to, yorto otherwise actuate a given instrumentality. By means of my invention', I am able to prevent the operationof any armature by an impulse to which said armature is not intended to respond'. I am .therefore able to insure positive and certain'selection, and to obtain a ywide range of selectivity. As has been indicated, one of the important uses to which I apply my invention is in the selection of .printing characters at the receiving end of a printing telegraph system, in which a onewire line is used.

It will be understood, however, that my invention may be applied equally as well and withv equal facility, and is adapted for use with apparatus other than printing telegraphs such as for instance, telephone party line systems, and other systems iny which simple and inexpensive but positive and accurate selection is essential. The `various objects of my invention will be clear fromlthe description which follows and from thedrawing, in which Fig. l is a diagram of my new system showing a preferred form and arrangement of the various selecting and operating means andthe circuits therefor diagrammatically.

In tha-t practical embodiment of my invention which I have'illustrated by way of eX- ample, I, have shown a series of six selecting magnets. e It will be understood,however,that the number of such `magnets and the corresponding parts to make up the full units therefor may be very greatly increased, and that by reason of the efficacy of my invention,

it becomes possible to use any number whichk may be needed for practical purposes, withg out'departing from the spirit and scope of the invention.

As has been previously indicated, my apparatus is based on the principle of neutralization ofthe magnetic force of a selecting magnet having a pair of windings,vone of which is energized by a currentof predetermined value, and the other of which is energized by a marginal impulse sent over the line to induce a magnetic force ropposed to that induced by the first winding. The armature of a given selecting magnet may therefore be magnetically released by a given marginal impulse. Another magnet then becomes operative to throw the released armature into position for causing the operation of the particular instrumentality intended to be responsive to the given impulse. Since the various selecting magnets are each substantially identical in construction, as are each of the various armatures and each of the magnets for moving the armatures into loperative position, which magnets I will hereinafter refer to as the auxiliary magnets a description of one unit, including a selecting andauxiliarymagnet and an armature therefor, will suiiice for all.

Each of the selecting magnets suchl as A preferably consists of a winding hereinafter referred to as the line winding, energized by the impulse, sent over the line in a manner Well known in the art, and as Will be briefly describedV hereinafter, ak winding 11y tending to oppose the eil'ect ofthe winding 10, and a core 12 on which the windings 10 and 11 are preferably wound. The line winding 10 as well as the other similar windings20, 30,

40, 50 and 60, no matter how many are used,

simultaneously receive from the lineV the characteristic impulse which may be. of greater or lesser predetermined current value, and are wound about the .substantially parallel legs oi 1Lhe generally U-shaped core 12. The

Winding l1, as illustrated, is 'preferably wound about the ycontinuation or cross bar 13 1 of the core 12 ofthe winding 10 and as shown is in spaced relation to and with its" axis at vright angles to the axis, yof the windings 1Y0 Vto minimize possibility of magnetic induction, but regardless of itsposition is so `designed and arranged as to oppose the magnetic eilect induced bythe winding 10, in a i manner which will be obvious to those skilled in the art#y Llt thereby becomes possible to so energize'the windings 10 and 11 that there is noresulting magnetic field to attractv the armature 14.- In other words, the 4magnetic kse force of the magnet A may be balanced,

neutralized or counteracted to reduce the* intensity lofthe field of thema'gnet to zero, provided that the proper current values are supplied to said windings simultaneously;

VToward this end, the winding 11k receives its energy ironia suitable source of power, such vas the lield or home battery 4 preferablythough'not necessarily through ythe inter# mediary of the rheostat, or resistance 15, so

` that said ywinding 11 is conseantly energized toexert a magnetic force "on the armature equal but opposite inpolarity `to that exerted Von the armatureby the line current impulses in the winding 10. Sirnilarly,'the windings 21, 31, 41, 5l and`61 through their respective resistances 25, 35, 45, and 65er through other suitable means are each energized'vvith current of a predetermined value suiiicient to armature to beoperated is thereby selected.` rllie transmitting or sending devices for sending over the line impulses of dilierent current strengths comprises briefly, the conductor 90 connected to the line and to the sending keys` y. A', B', C', D5, EQ-andll", through theintermediary of the respective resistances 17, 27,

37 47, 57, and G7, the resistance 17 being the i greatest so as to send the smallest impulse and the resistance' being least to'send the great-- est impulse.

It will be understood that while I prefer to pivotally supportthe various armatures such as 14, they are otherwise free'offall mechanical restraint except that exerted upon them by their selecting and Vauxiliary magnets. Any armature is'therefore operative byV its auxiliary magnet only when it is magnetically released VVjby the neutralization of its selecting magnet so that the armatures tend to remain in the various positions into which they y are 'moved While'all the armatures are biased towards their respective backstops 19, 29,l 39, 49, 59

and 69, owing to the constant energization of the windings 11, 21,731, 41, 5 1 and 61, the -se lecting armature, even though releasedk by the neutralization of the magnetic iieldin which it is located, remains'biased towards its selecting magnet, and does .not move, unless itis vpositively moved by suitable means. VVhileit is customary inmagnetic armatures to use springs' or other, similar mechanism Jfor theV purpose of operating the armature Vafter it has beenlreleased by its magnet, lpi'efer to avoid the use of'springs for that purpose, since, as will be explained hereinafter, the Valuesof the magnetic forces acting on more vthan one armature may momentarilyk be reduced to zero and thereby give the spring the opportunity to operate the wrong armature. p

It a current impulse ofhigh value is sent over the line, one of the line windingsy as 10 will develop a .field of greater intensity than that developed by the field Winding 11, which is constantly energized to induce a magnetic lield of lower intensity than those induced by the corresponding ield windings 21, 31, 41,

51 and 61; It will be seen that before lthe impulse isreceived by the winding Y10, the intensity of the iield is entirely dependent on the winding 11. On the receptionby' the 4vwinding 10 of the iinpulsefof comparatively high current value, the intensity of the result- Y ing field is first reduced, d'ue tothe `forcel induced by the winding 11 being lirst overcome on the building up Voi the magnet-ic'force of the winding 10,' and for a very small, though hardly appreciable instant of time may be precisely neutralized or reduced to zero,after which themagiietic force, dueto the impulse, Ywillreach its` full strength of opposite poi-Yy larity to that exerted by the magnet Awhen the winding 10 is deenergized, and will'again be operative to attract the armature. That is, the instantaneous yvalues of the magnetic `forces operating upon more than one arn1ature may become zero in response to a marginal impulseof greater than the lowest predetermined value.

It springs or similar mechanical devices were used, it might be' possible thatV during the moment in which the intensity of the magnetic field is reduced to zero, the spring would act to move the armature 14 away from the selecting magnet and thereby causing momentary operationy of the wrong instrumentality, which it was not intended to select. I'provide against this contingency by the use of a series of' auxiliary magnets such as 16, 26, 86, 46, V56'and 66, each preferably arranged on the other side of the respective armatures 14, 24, 34, 44, 54 and 64, and each designed-to act after the various magnetic fields have reached their respective final intensities. The various auxiliary magnets 16, 26, 36, 46, 56 and 66 are shown connected inkseries and receive energy from a suitable source of power such asthe battery 8, but said magnets may just as well be connected in parallel or in series parallel if desired.

The auxiliary magnetshave the further advantage over springs or similar mechanical devices and over gravity operation of the armatures Vin that the only forces acting upon the armatures are vmagnetic forces induced in the selecting magnets or in the auxiliary magnets. These forces act upon the selected armature alternately and at different times in a manner impossible with springs which must oppose operation by one set of magnets. If there should be any period when neither the auxiliary nor the selecting magnets are acting upon the armatures, the armatures are free of all forces and it therefore requires but a comparatively small magnetic force to move them in either direction, the armatures remaining or being maintained by inertia in the positions in which they are posiF tively moved by the magnetic forces thereon. It therefore becomes possible to movethe selected armature into its initial biased position immediately after its release by the afuxiliary magnet after the termination of the impulse since the selecting magnets operate instantaneously owing to their constant energization after the'termination of the impulse, and no time is lost as would be the case if the force of the selecting magnets were opposed by a spring or by gravity. It will therefore be seen that my device is possessed of high sensitivity and that the clearing operation can be carried out at high speeds and much greater speed than is possible if springs or gravity were to oppose the movement of the selected armature toward the selecting magnet therefor.

To retard the action of said auxiliary magnets as above described, a suitable relay as 6 is arranged in the line, preferably in advance of the selecting magnets. The relay operates upon its armature 7 to close the normally open circuit in the battery line 5 when an impulse is sent over the line. It will be seen that owing to the time element involved in the movement of the relay armature 7 against the action of its spring to close the circuit to the auxiliary magnets, the auxiliary magnets are energized somewhat later than the selecting magnets. It follows that whenthe instantaneous value of the magnetic forces exerted by any of the magnets A, B, C, D, E and F upon their armatures becomes zero, the auxiliary magnets have not yet been energizedy Untilithe intensity of the magnetic field in which the selected armature is arranged, reaches its limit of in-l 75 tensity or final intensity resulting from the combination of impulse and the home or field current, said armature is not acted upon by its auxiliary magnet( To further assure this result, the auxiliary magnets 16, 26, 36, 46, 56 and 66are so energized as to create a magnetic field of less intensity than the limiting, or minimum final intensity of any of the fields produced by any of the magnets A, B, C, D, E and F at any time. In other words, the operationfof a selected armature by the auxiliary magnets is independent of the instantaneous or intermediate values 'of the magnetic forces operatingy upon the armatures, but dependent only on the final values l thereof. Operation of the selected armature byL its auxiliary magnet closes the circuit to an instrumentality such as a of any desired type, such as for instance, a given printing character of a printing telegraph. 35

It will be understood that when the line impulse ceases, the relay 6 releases the armature 7 thereby cutting off the current received by the auxiliary magnets from the battery 8, and allowing the selecting magnet to draw its armature back against its backstop ready for the reception of another impulse and the selection and operation of another instrumentality.

The various circuits will now be. described.

As has been heretofore explained, the various line windings 10, 20, 30, 40, and 60 are connected in parallel to the line as by means of the conductors and 71, the former conductor being connected to one end of each of the line windings and the latter conductor 71 being vconnected to the other ends of each of the line windings and grounded as at 72. The relay-magnet 6 is also connected in parallel to the line as by means of the conductors 73 and 74 so as to become energized simultaneously with the energization of the line windings 10, 20, `30, 40, 50 and 60 by an impulse sent over the line.

The field windings 11, 21, 31, 41, 51 and 61 are connected in parallel with the field or home` circuit energized by the battery 4 through the conductors 75 and 76. The conductor 75 is connected to one end of each of the field windings and leads to one side of the battery 4 while the conductor 76 is con` nected to the other end of each of the field windings and leads to the other side of said battery.

The auxiliary magnets 16, 26,- 36, 46, 56 and 130 gli 66 are energized by the battery lltlirough the conductors Wandl 781and as illustratedare connected lin*y series to theV conductor ,78 through the conductors7980, 81, 82, and 83, which are each connected toa terniinalioi:l

veach ofthe adjacent magnets. The conductor. '.7 8 is connected to a'suitable terminal on `therelay armature 7 andthence through the @armature Z and the line y5, leads to Oneside of the 'battery-while the conductorl 7T-.leads tothe other side'of said battery.A The circuit is normallv opened-by the relay armature 7 butis closed when the relayy 6 is energized by the impulse senty overI the line. A

kAs has beeni eXplained,;said magnets are energized later than the line windings 10 due tothe fact that the operation of the armature Toithe relay is not instantaneous'fAs has been'` heretofore pointed out, the auxiliary magnets, instead ofA being connected in `series yas shown, fmayxjust aswell be connected in parallel toltlie conductors 77 and 78 Vor in series parallel, if desired.

`The selecting instruments a, b, c, d, e and f :indicated: diagrammatically, may bev of 4any type suchv as the printing cliaracters'of -a printing telegraph and are energized by a suitable battery suclias the battery 3 through the conductors V8O and Sly to which they are connected. The circuit to the selecting instruments is normally open due to the normal biasot the armatures 14, 24, `34, 44, v54 and 64tovvard the lield windings, ysaid ,arma- Vtures .normally resting vunder the influenceV of the field vwindings against ,theirv respective back-stops 19, 29, 39, 49, 59 vand 69. On Vthe Y neutralization of the proper selecting magnets A, B, C, D, E and F theVV selected armature isfreleased and is then moved by its auX- iliary magnetto closethe circuit-to the selected-instrument a, Z2, c, Le orf. y

.It will be seen that l havefdevised simple land efcientmeclianism. capable of a wide vlange oi'i selection :for operating,v any one of any number of instru-mentalities ywith certainty, that ,by reason of my invention, it becomes impossible to operate, the wrong instrumentality and that I have4 devised a system well adapted to meet the severe requirements of practical use. l do not Wishvto beV understood as limiting myself tothe use of my system for printing telegraphs only, as said system has many otlier'uses, and yIV further do not wish to be understood as limiting myself to xtlie'speciiic structure and arrangement herein shown and describedlin detail since I intend to claim my invention as broadly as y,may be permitted bythegstate of the 'prior lart andthe terms of the appended claims. C

,-Ielaiin:` l y u Y, il .1. In an electrical system in which any one of .any number of selecting `devices isfresponsive to a single impulse of given current valyuedelivered'theretoover a single wire, and

the other devices are each responsive respectively to impulses of different currentva-lue, a series` of selecting vmagnets receiving said impulses, means for neutralizing the magnetic' ield of only one of said magnets by said limpulsa/an armature foreach or saidV magnets normally biased toward its selecting magneta Aseries of auxiliary magnets each arrangedto operateV upon vone of said armatures, and ymeans responsive to the impulse for energizing said lauxiliary magnets Vfor operating the armature vof the neutralized magnet only.

2. In a. one-wire line electrical selecting system, a series of electro-magnets, each provided with a line winding and a field Winding, means for energizing the lield winding Y or eacli of said magnets with current of different predetermined value fromthat of tlie l'leld windings oftheother magnets, the'line winding of each magnet beingenergized by a single yimpulse sent over tli'ev line of such current value as to cause the-magnetic field of only a single magnet to be nullified'by'a given impulse, an armature for each magnet,

a setie auxiliary magnets each arranged to operateupon' 'ene of the armatures, and a relay in tlie line operative to close a circuit to the auxiliary magnets in response to the impulse. fr Y n 3. In' la marginal selecting system of the ycharacter described, a series of armatures subjected only to magnetic forces, electro-magnets each provid-ed with line and ield windings, and normallymaintaining the armatures in inoperative position and biasedjtoward they magnet, means for supplying current of' predetermined current value to the field winding ofeach of said magnets to cause each of said field windings to exert a magnetic force diering in intensity from that of the others, means for connecting the line winding oit each magnet tothe line for delivery thereto of an impulseV of predetermined current value sum-y cient to exert a vmagnetic force equal to that 4character described, a series of armatures,

means for normally attracting each of said armatures, means for neutralizing the magnetic force acting on one of said armatures on. the delivery to said neutralizing means of a given current impulse of given current value sent over the line, including means for receiving current impulses of predetermined current value from the line, and means for supplying to said current receiving means,

current of the proper value to finally neu-l tralize the magnetic eiiect ofthe armature attracting means, and electromagnetic means responsive'to the impulse for attracting that armature, the magnetic ield of which has been iinally neutralized.

5, A marginal selecting system, receiving single selecting impulses of diierent respective predetermined current values `from a onewireline, comprising a series oit' switch members, movable from normal and inoperative position to ,circuit closing position, a series of electro-magnets each arranged to move a sclected oneof said switch members and each having a magnetic circuit, and a line winding therefor energized by said impulses, and having a field winding energized by a eld current of the properV predetermined value to oppose the magnetic forces set up ineach ofnsaid electro-magnets by -said line wind ing, land thereby reducing the final magnetic forceiof only a selected one of said electromagnets substantially to zero in response to agiven impulse received by said line windings, and releasing the magnetic force exerted on one yof saidswitch members, means for magnetically operating the released switch member to move it to circuit closing position in response to said impulse, independently of the instanteous values of the magnetic forces operating upon thek remaining switch members, and means for pivotally supporting said switch members for the movement mentioned, said switch members being otherwise free of mechanical restraint.

6. A marginal selecting device for an electrical system wherein yselecting impulses of predetermined different current values are received singly by the device from a single line, comprising a series of switch members biased to one position and free of forces other than magnetic tending to change the positions thereof, electro-magnetic means, including line windings energized by said impulses, and field windings energized to produce an opposite magnetic eect, for retaining the bias of all but the selected one of said switch members and finally neutralizing the bias of and magnetically releasing said selected switch member in response to the impulse, electromagnetic means for moving only the switch member so selected, independently of the instantaneous values of the magnetic forces operating upon the remaining switch members, and means for energizing said last-mentioned means in response to the impulse only.

7. In a marginal selecting system of the character described, a series of movable circuit closing members pivotally mounted free of mechanical restraint, a series of electro` magnetic elements, each having aline winding receiving oneL marginal impulse of predetermined current value at a time from the line, and eachl having a second winding energized by a current of predetermined current value to exert a magnetic force upon one of said members equaland opposite to that exerted by the .Sine winding under vthe influence of a givenv impulse, and a magnet for each of said circuit closing members, responsive to the marginal impulse for moving only a selected one of said circuit closing members to circuit closing position when both windings of the electro-magnetic elements acting upon the selected member have been energized to iinaily neutralize each other, said magnet operating independently ofthe instantaneous values of the magnetic forces exertedon the remaining elements, and means responsive to the impulse for energizing said magnets after said lwindings have been neutralized, said magnets and said elements acting at difier-l ent but closely spaced times in response to the impulse, and the forces exerted thereby being unopposed except by the inertia of the selected member.

8. In a marginal selecting system, a series of circuit closing members, magnetic means adapted to have the magnetic effect thereof finally neutralized for freeing one of said members in response to al givenimpulse of given currentl value received by said means, electro-magnetic means for operating the treed member to close a selected circuit independently of the instantaneous values of the magnetic forces exerted on the remaining members, and a circuit for energizing said electro-magnetic means in response to the impulse and after theimpuise has had its full effect on vthe first-mentioned magnetic means including a normally opened relay in thecircuit adapted to close thecircuit on the reception by the relay of the impulse. i

9. In a marginal selecting system of the character described, aseries of circuit-closing armatures,,electromagnetic means for attracting said armatures to move them in one direction, electro-magnetic means energized by van impulse of given current value delivered thereto for freeing a given armature of the attraction of said attracting means and of all forces acting thereon in response to a given impulse, and operative at a different time to free anyselected one of the other armatures respectively in response respectively to other single given impulses of different current val# ue, and electromagnetic means responsive to the impulse for moving the selected armature in the other direction immediately after it has been freed. i

l0. In a marginal selectingl system Aof the character described, a series ofy armatures normally biased to circuit opening position, means for magnetically releasing any one of said armatures in responseto respective im- Las pulses of different current value delivered lto saidmeans, and a series of magnets each acting yon one of the armatures for moving only the released armature to close a circuit, each of saidy magnets exertingv'a magnetic force upon itsv respective armature in response to the 'given'impulsm saidy force being oi'v less inf tensity thanthe inal streiigth of the minimum magnetic forcey acting'on any but the selected armature at any time.

11. yIn 'a marginal selecting system of the character described, a series of armatures,n or

, mally magnetically biased'to circuit opening position, and acted upon by ymagnetic forces only, a series of instrumentalities to be operated, means for freeing different selected armatures of the bias thereof in response respectively, to impulses of different current valuedelivered to said means, and magnetic means responsive'to the impulse Vorinoving tlie selected treed armature to close a vcircuit to a' given instrumentality, ysaid -magnetic means operating 'only' after I the magnetic 'forces on all but they freed armaturehave reached their maximum value and for .releasing the the freed armature rto'befco'me unopposedly biased into its initial position immediately on the termination of the impulse;

12. Ina marginal selecting system of the characterdescribed, aI series of pivoted circuit closing members, otherwise free, of mechanical restraint ,and magnetically biased tov circuit opening position, means responsive to anfimpulse of given current valueA lio-r Vfreeing any number of ythe bias thereof by the neutralizationof the magneticforce vacting on the selected member, including magnetic means exerting predetermined magnetic Yorces on one side of said members and magnetic means energized byimpulses of predetermined value suilicient to producea final magnetic force of Y such intensity and direction as to precisely balance the effect of said predetermined mag netic means With respect to onlya selectedV one'of said members, magnetic means on the other side of saidv members for moving the selected member to circuit closing position, responsive to the impulse and inoperative to ymoveV any unselected member irrespective of the intermediate value of the magnetic forces acting on the unselected members, and releasing the selected member immediatelyon theV termination of the impulse to permit said member to be unopposedly biased to its initial i position, and a rela-yresponsive to the impulse vfor energizing the last-mentioned magnetic means vo-nly after the final values ofthemagnetic forces on all but the selected members have been reached to create a magnetic iield of less Vintensity than the minimum of said iinal values, said members beingmaintained by inertia'intlie positions into which they are moved until subjected to magnetic force.. n v13. The method'of selecting a device to be operated from a number of suchl devices in a marginal selecting systemV wherein selecting impulses of different .currentvalues' arere-` ceived singly by thedevices from a singlevline comprising subgecting the devices to electromagnetic torce only, the force acting on any oi'' the devices being` of different intensity from the force acting on any other of the de-V vices,neutralizing the electromagnetic Vforce acting on the device to be selected in response to an impulse to :tree the device fromr all torce including the electromagnetic force, then by lmeans of the Y impulse exerting,l electromagnetic ,force on the device tol be selectedthe oppositedirection to operate the deviceV in VV response to said impulse and only after the 14., ln a marginal selecting system, a series of movable circuit-closing pivoted members Votherwise free oi"- mechanical restraint, means for normally exerting magnetic force upon said members, meansy for neutralizing the force exerted upon any selected member 'in response to a given impulse, delivered to said neutralizing means, electromagnets arranged adjacent said members for moving the selected member, and means for energizing lsaid electromagnets Vin response vto the impulse to iceY create a magnetic `field of less intensitythan the minimum iinal intensity exerted by said v-first-inentionedmeans in response to ythe im-` iio 

